Tuesday, July 28, 2009

This post reports my finding that push notifications in the sandbox environment don't work on hacktivated iPhones, even with the Push Fix package.

I spent a lot of time developing code for Push Notifications, because I was debugging my code under the assumption that Push Notifications work on my iPhone. I hope this post saves some time for other iPhone SDK developers.

Test Environment
I used an iPhone 2G (hardware model iPhone1,1) which was never activated with AT&T. The phone was connected to the Internet via WiFi, and it had no SIM card in it. My control is a newly bought iPod Touch 2G (hardware model iPod2,1) was activated with iTunes, upgraded to iPhone OS 3.0, and connected to the Internet via the same WiFi router.

The iPhone was jailbroken, hacktivated, and unlocked with Pwnage Tool 3.0, and it received Push Fix from the iPhoneil.net repository. I used AIM (the free edition) to confirm that Push Notifications work on the iPhone.

I used ZergSupport's test suite to collect the push tokens for the iPhone and iPod, and I used imobile's test suite to send the push notifications.

Test Results
The hacktivated iPhone never received notifications from the sandbox (a.k.a. development) servers. It did receive notifications from the production servers. The iTunes-activated iPod received both development and production notifications.

Conclusion
If you're considering developing for the iPhone, and you want to implement and test Push Notifications for your application, you'll need an iTunes-activated device. The cheapest option is probably an iPod Touch 2G.

Motivation
I can't afford an iPhone. I can afford the device, but I can't afford AT&T's plan. On the other hand, I want to address the iPhone's user base, because it consists of wealthy people who spend money easily.

I have an iPhone 2G, from the good days when you could buy one in an Apple store, and not have to deal with AT&T at all. I like testing my application on its EDGE connection, to ensure they behave under the worst-case network connectivity scenario.

Saturday, July 25, 2009

This post contains a command that you must absolutely issue if you are a Ruby developer upgrading to Snow Leopard.

The CommandsUpdate: Type the following command in terminal:

sudo gem update --system; sudo gem pristine --all

rubygems will produce some errors which are safe to ignore

For historical reasons, here's my initial solution to re-compiling all the native gems.
Fire up irb, and type the following command:`gem list`.each_line {|line| system "sudo gem install #{line.split.first}"}

Motivation
Snow Leopard introduces a disrupting change: everything runs in 64-bit mode by default. Most importantly to me, ruby is now 64-bit. This is a problem when upgrading to Snow Leopard, as opposed to doing a fresh install, because the Ruby extensions in your old gems are probably 32-bit.

A quick solution to this problem is getting all the extensions rebuilt, which is done by reinstalling all the gems.

In case you're wondering, gem update won't do the trick, because it will not rebuild all your gems.

Symptoms
If you're lucky, you'll get a library loading error when trying to use some gem with an extension (example: json), and you'll figure out rather quickly that you need to reinstall the gem.

A subtle symptom of the same bug is experiencing slowdowns running a Rails development server. In my case, webrick was really slow - start-up took about 30 seconds. For this reason, it's better to re-compile all the gems, as oppose to fire-fighting load error messages.

Saturday, July 11, 2009

One-line Summary
If the TubeTV download button is disabled in a YouTube video page, refresh the page (Apple+R) and hit the button while it's available.

Whole Story
I use TubeTV to download music videos those funny user-generated videos from YouTube. I've set it to encode the videos for my iPhone, then them directly in my iTunes library, tagged as Music Videos. Amazingly, it was released in early 2008, and it's still avoiding all the crap that has come to YouTube since (annotations, ads). Thank you YouTube for not tampering with the H.264 stream in the Flash files!

I usually wait until the YouTube video loads completely before I hit TubeTV's download button, so I don't download the same bits twice. But, as of recently, I've noticed that the download button becomes disabled at some point during the video's load. I was scared for a second, and thought the days of my easy downloading are over.

After my 2-seconds panic went away, I tried refreshing the page, and the download button was enabled again. The videos are still downloaded, encoded for iPhone, and deposited into iTunes' library just fine.

Closing Thoughts
Too bad TubeTV wasn't open sourced, even though looks like its author abandoned it. One day, it will stop working. Hopefully, something better will be written by then. Or YouTube will start using <video> tags and serve us the H.264 data on a silver platter. And the RIAA / MPAA will let that slide. Right.

Short Bio

Victor Costan got infected with a passion for coding at the age of 10, and proceeded to earn a M.Eng in Computer science from MIT. Victor also holds a B.S. in Management that he pursued as he fell prey to the belief that great software requires legions of developers manipulating bloated code bases in repetitive ways. Thanks to Paul Graham's essays, Ruby, and Rails, he re-discovered the joy of coding, and came back from the dark ways of management.

Nowadays, Victor is still crazy about building software that he can impress his friends with, but he also dreams of contributing to making coding even more enjoyable. Victor likes developing mobile and Web 2.0 applications, and occasionally enjoys building some distributed systems behind the apps. When he is not coding, you will most likely find him reading up on some new programming language or software development technique.

At times, Victor likes to pretend he's mentally sane, and can be seen catching up with friends, watching a movie, or exploring Boston.